Fibular nerve damage is damage to the common fibular nerve or one of its branches. This nerve is located in the leg, beginning at the fourth and fifth lumbar in the spine and continuing down along the lateral side of the knee. It crosses over the fibula and winds around the calf bone, branching into the superficial and deep fibular nerves under the peroneus longus muscle of the calf. Damage to one of these three nerves can occur along any point of their length. Injury, such as a back injury or knee trauma, to any of these three nerves can lead to loss of sensation in the lower part of the leg and loss of foot movement.
The common fibular nerve is the main nerve that supplies the calf muscles with sensation and movement. Common fibular nerve damage can occur where the nerve begins in the spine, but most commonly damage to this nerve occurs from knee injury. Long-term compression of the nerve can also cause damage. Neuropathy, which is degenerative nerve damage, can be seen in people who are on bed rest for long periods, in some kinds of dancers, and in athletes who suffer from repeated over-extension of the knee. People who sit for long periods with their legs crossed may also suffer from damage to the common fibular nerve, particularly where the nerve crosses over the fibular head.
Superficial fibular nerve damage can be diagnosed based on a person’s history and symptoms. Damage to this fibular nerve is most commonly found in people who have repeated ankle sprains. In some cases, repeated and prolonged actions over the course of many years, such as squatting or kneeling, can also cause damage. Doctors believe that damage to this nerve occurs because the nerve is repeatedly stretched too far.
Repeated or particularly traumatic injury to the side of the knee is the most common cause of deep fibular nerve damage. This branch of the common fibular nerve is also more susceptible to nerve damage as a result of inflammatory conditions, autoimmune diseases, and lower motor neuron disease. Rheumatoid arthritis can lead to a damaged deep fibular nerve, but not often. Diabetes can also be a possible cause.
Regardless of which nerve suffers from fibular nerve damage, movement of the foot is affected. Damage to fibular nerves can cause foot drop, which is when the toe points downward and cannot be lifted easily. The back of the foot can lose sensation and feel numb. Commonly, pain along the calf muscles and knee area is experienced.
Treatment for fibular nerve damage can vary depending on the cause of the damage. For nerve damage that is a result of entrapment, decompression surgery can help. Physical therapy and nonsteroidal anti-inflammatory drugs, such as naproxen, are helpful as well. In some cases, doctors may decide to inject a steroid and lidocaine combination into the fibular area to reduce symptoms.